The present invention relates to an integrated optoelectronic device and a method for making an integrated optoelectronic device. Such a device includes electronic and optoelectronic components integrated with, e.g., glass or glass-like optic components.
Sophisticated and complex photonic signal processing architectures require physical properties and operational characteristics that are not present in one single material system. For this reason, there is great interest in methods to combine semiconductor optoelectronic devices with glass or glass-like integrated optic components.
A wide variety of applications for military and commercial systems and components exists that requires increasing levels of integration of optoelectronic devices. Integration of a variety of devices into a compact and multifunctional structure enables increased capability for sophisticated signal processing in a manner that is compact and results in minimal requirements for component mass and DC power. These considerations are critical cost drivers for many sensor and communication applications where compact integration facilitates things such as personal communication handset miniaturization or space deployment of network assets.
Heterogeneous integration is most typically accomplished using silica-on-silicon waveguides. The semiconductor chips are usually aligned in a flip chip configuration and bump-bonded to the silica-on-silicon waveguides.
However, with heterogeneous integration of semiconductor devices with silica-on-silicon, high processing temperatures dictate that the passive-optical waveguides (i.e., silica-on-silicon) be made first, followed by alignment and bonding of the semiconductor chip.
The present invention relates to an integrated optoelectronic device and a method for making an integrated optoelectronic device. The optoelectronic device includes a substrate, at least one optoelectronic component provided on the substrate, and a waveguide provided on the substrate and optically connected to the at least one optoelectronic device. According to the present invention, the waveguide is made of a sol-gel glass.
The method for making an integrated optoelectronic device includes the steps of providing a substrate, providing at least one optoelectronic component on the substrate, and providing at least one waveguide on the substrate and optically connected to the at least one optoelectronic device. According to the present invention, the waveguide is made of a sol-gel glass.
According to certain embodiments of the present invention, the optoelectronic component can be a semiconductor chip, e.g., made of a III-V semiconductor material. The semiconductor chip can be mounted top side up on the substrate. At least one optoelectronic component can be an array of semiconductor waveguide devices.
According to certain embodiments of the method for making the integrated optoelectronic device of the present invention, the step of providing at least one optoelectronic component on the substrate includes etching a recess in the substrate, the recess having a depth less than the thickness of at least one optoelectronic component, and affixing the optoelectronic component in the recess so that an upper surface of the optoelectronic component extends above an upper surface of the substrate.
The method can further include the steps of forming a vertical alignment layer over the substrate, and providing the vertical alignment layer with a thickness sufficient to allow the upper surface of the at least one optoelectronic component to extend above an upper surface of the vertical alignment layer. This can be accomplished by flattening the upper surface of the vertical alignment layer after it is formed-over the substrate, then etching the vertical alignment layer over the substrate until the upper surface of the optoelectronic component is exposed, and then performing a timed etch to provide the vertical alignment layer with the thickness sufficient to allow the upper surface of the optoelectronic component to extend above the upper surface of the vertical alignment layer.
The at least one waveguide can be provided on the substrate by coating a sol over the upper surface of the vertical alignment layer, curing the sol to provide a sol-gel glass layer, and patterning the sol-gel to provide the at least one waveguide. A sol-gel cladding layer can be provided on the vertical alignment layer before providing the at least one waveguide, and waveguide provided on the sol-gel cladding layer.